Fixing leaky handling of SkImage in SkDeferredCanvas.

include/pipe/SkGPipe.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 
 #ifndef SkGPipe_DEFINED
@@ skipping 69 matching lines @@
     /**
      *  This is called each time some atomic portion of the data has been
      *  written to the block (most recently returned by requestBlock()).
      *  If bytes == 0, then the writer has finished.
      *
      *  bytes will always be a multiple of 4.
      */
     virtual void notifyWritten(size_t bytes) = 0;
     virtual int numberOfReaders() const { return 1; }
 
+    /**
+     *  Release resource references that are held in internal caches.
+     *  This must only be called after the pipe has been completely flushed.
+     */
+    void purgeCaches();
+
 private:
     friend class SkGPipeWriter;
     void setCanvas(SkGPipeCanvas*);
 
     SkGPipeCanvas* fCanvas;
 };
 
 class SkGPipeWriter {
 public:
     SkGPipeWriter();
@@ skipping 59 matching lines @@
 private:
     enum {
         kDefaultRecordingCanvasSize = 32767,
     };
 
     SkGPipeCanvas* fCanvas;
     SkWriter32     fWriter;
 };
 
 #endif